and Laboratory Methods. 



2575 



1. Sketch the entire moss, showing the gametophyte and the sporophyte 

 with the capsule and the very large, pyriform, fleshy hypophysis. Describe. 



2. Sketch the capsule and hypophysis under low power, carefully repre- 

 senting the shape and surface details. 



8. Examine the surface of the hypophysis under low and high power and 

 note the stomata. Draw a small portion of the surface, showing stomata. 



4. Note. — The large hypophysis covered with stomata and filled 

 with loose tissue is well fitted for the work of photosynthesis and 

 may be looked upon as foreshadowing the leaf structure found in the 

 ferns and other higher plants. 



LIII. Splachniim litteitDi L. or 5. riibrnm L. 



These remarkable mosses are rather uncommon, and very few 

 will probably be able to collect specimens ; nevertheless an effort 

 should be made to obtain fresh or alcoholic material of plants with 

 nearly mature sporophytes. They are reported mainly from the 

 Rocky Mountain region. 



1. Under low power make a careful drawing of the sporophyte, 

 showing the foot, the seta, the large umbrella-like hypophysis, and 

 the capsule (Fig. 10). 



2. Draw part of the surface of the hypophysis under high power, 

 showing the stomata. Are the stomata both on the upper and lower 

 sides ? 



3. Compare the hypophyses of Hypmim radicale. Polytrichum \ 

 commune, Splachmim ampullaceum, and Splachniim liitenm and note O 

 the progressive development of the hypophysis as represented by Fig. 10. 

 these types. From this comparison it appears that the hypophysis Sporophyte 

 may be regarded as a nascent, transpiratory and food-manufacturing 

 organ. 



LIV. Anthoceros kevis L. or A. punctatus L. 



Class, Anthocerotes. Order, Anthocerotales. Family, Anthocerotaceae. 



The horned liverworts are common on wet banks and sandstones ledges, 

 especially around springs in shady places. The gametophyte is a small, lobed, 

 more or less disc-shaped thallus from which the sporophytes extend upward like 

 small vertical horns. 



1. Under dissecting microscope, sketch a gametophyte containing nearly 

 mature sporophytes. Note the thick tubular sheath around the base of the 

 sporophyte. 



2. Mount a small piece of the thallus and under high power draw a cell 

 showing the single large chloroplast. Compare these cells with those of Coleo- 

 chaete. 



3. Look for endophytic colonies of a blue-green alga (Nostoc) in cavities on 

 the under side of the thallus. 



4. Separate a sporophyte, which is just mature at the tip, from the gameto- 

 phyte, being careful to keep the foot in a perfect condition, and sketch under low 



num 

 luteum. 



